I heard a possibly apocryphal story about finding leaks in military transport aircraft -- they'd toss rolls of toilet paper around inside the craft and watch fo

I heard a possibly apocryphal story about finding leaks in military transport aircraft -- they'd toss rolls of toilet paper around inside the craft and watch for it drifting toward and sticking to the inside of the fuselage. Apparently there was a particularly bad leak one time that simply ate the entire roll was consumed with a "FWUMP".